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No. 624,667. Patented May 9, I899.

.c. J. MELLIN.

OVER'PASS VALVE FOR LOCOMOTIVE ENGINES.

(Application filed Dec. 29, 1897.)-

(No Model.)

WITNESSES:

ATTORNEY THE NORRIS PETER$ w. moro umnv, wnsumumu. n, c.

NlTED STATES PATENT OFFICE.

CARL J. MELLIN, OF RICHMOND, VIRGINIA, ASSIGNOR TO THE RICHMOND LOCCMOTIVE AND MACHINE WORKS, OF SAME PLACE.

OVERPASS -VALVE FOR LOCOMOTlVE-ENGINES.

SPECIFICATION forming part of Letters Patent No. 624,667, dated May 9, 1899.

Application filed December 29, 1897. Scn'al No. 664,16 7. (No model.) h

To all whmn it may concern:

Be it known that I, CARL J. MELLIN, a citizen of the United States, and a resident of Richmond, in the county of I-Ienrico and State of Virginia, have invented certain new and .useful Improvements in Overpass-Valves for sar lar e assa es and even an inte ral valve device contrived for automatic action involves complications of construction which it is desirableto avoid.

To these ends my invention consists of a simple contrivance of an integral overpassvalve attachment with a valve to be actuated by a hand-lever in the cab, as hereinafter described, reference being made to the accompanying drawings, in which-- Figure 1 is an end elevation of a steam-cylinder and part of the saddle of a locomotive, showing the application of my improved overpass apparatus, the steam-chest being removed. Fig. 2 is a vertical longitudinal section on line 2 2 of Fig. 1, including the valve. Fig. 3 is a horizontal section on line 3 3 of Fig. 1.

The valve-cylinder a is cast, together with the steam-cylinder 6, along the outside of the main port-casing c and below the valve-face d in about the same arrangement as represented in my Letters Patent on an automatic overpass-valve device, No. 587,505, dated August 3,1897; but in this case only the ports 6,

communicating with the live-steam ports f, are

. provided. The otherports of that patent c0111- municating with the steam-chest and always open to live steam are omitted, not being necessary in this invention. Between'the junctions of these ports with the valve-cylinder said cylinder is chambered at g for free communication between them when desired, and

a piston-valve having heads h and 2', adapted r to open and close said ports and afford com munication between them when they are to be opened, is applied in said cylinder, said valve being provided with a rod j for connection with a lever in the cab-in any of the wellknownways to enable the engineer to operate the valve at will. The part of the valve-cylinder containing head h is a little larger than the part containing head 2', and a shoulder is provided at for a seat, whereon said head It --may close a little more effectively than without such seat, particularly if the lever-latch is madeto hold the head h against said seat .with some pressure, as if the lever be sprung forward a little after the head lodges on the seat to engage the latch in the notch of the latch-holding bar.

It will be understood that when the valve is in the position represented in Fig. 2 the overpass isclosed for the regular operation of the engine; but when the valve is shifted back to the position represented in Fig. 3 the overpass is open for the air or vapor to pass from one side of the piston to the other when steam is shut oft and the engine is drifting to relieve the piston from excessive resistance and prevent an excessive amount of cold air from entering the cylinder through the exhaust-passage.

I claim The improved overpass attachment for steam-engines consistingof the combination with the cylinder, of the overpass-valve case located in and formed integrally with the cylindencasting and having ports respectively communicating with the cylinder steam-ports and an independent overpass valve in said 

